A targeting construct was used to insert an IRES-cre-FRT-pgk-neo-FRT cassette into the Kiss1 locus after exon 2. Properly targeted ES cell clones were injected into C57BL/6J blastcysts to produce KissICneo+ chimeras that were backcrossed to C57BL/6J animals. To remove the neo cassette, mice were bred to Flp deleter mice, then backcrossed to C57BL/6J for 6 generations. (J:167285)